Up periscope! with America's favorite armchair technowarrior, who here, with the cooperation of the Navy, takes readers deeper than they've ever gone inside a nuclear submarine. Clancy's fascination with underseas combat dates back at least as far as his debut novel, the sub-set The Hunt for Red October, and you can sense his pride and excitement as--after a brief but well-informed survey of the history of submarines and of a submariner's training- -he takes us aboard the USS Miami, an Improved Los Angeles-class boat berthed at the US Submarine Base in Groton, Connecticut. Those who share Clancy's almost erotic admiration for technology won't be disappointed by the tour: "It is easy to tell that the Miami is equipped with the Mk 32 VLS system, since it is sitting level in the water," he tells us at once, adding that the "33-foot- diameter hull is...approximately 3 inches thick and composed of HNY-80 high tensile steel." But fans of human-interest also will find that's engaging here, as the author notes, for example, that life aboard the Miami is akin to "a combination of living in an oversized motor home and summer camp," with no privacy but much esprit de corps, where sleep deprivation is a major problem but dining is "a pleasure," except for the preponderance of three- bean salad and the horrid-tasting orange "bug juice"--which however, makes "an excellent scouring powder for cleaning floors and heads." Clancy follows up his tour of the Miami with a briefer one of a British sub; a rundown of various submarine missions; and glances at other countries' submarines (Sweden, it turns out, has a formidable sub force). All in all: a fast-paced silent running that will please many of the author's fans--enough, perhaps, to allow a surfacing on the bestseller lists.